Half to william h



(No Model!) J. N. ROBERTS.

BOILER.

' Patented Dec. 17, 1889.

m 0 T N E V N l A TTOR/VE Y 8.

; UNITED STATES:

PATENT OFFICE.

JOHN NELSON ROBERTS, OF BRAINERD, MINNESOTA, ASSIGNOR OF ONE- HALF ToWILLIAM H. sTU eEoN, OF SAME PLAOE.

BOILER.

SPECIFICATION forming part of Letters Patent No. 417,443, dated December17, 1889.

' Application filed June 28, 1889. Serial No. 315,883. (No model.)

To aZZ whom it may concern.-

Be it known that I, J OHN NELSON ROBERTS, of Brainerd, in the county ofCrow Wing and State of Minnesota, have invented certain new and usefulImprovements in Boilers, of which the following is a full, clear, andexact description.

The Object of the invention is to provide certain new and usefulimprovements in locomotive and stationary. boilers, whereby sufficientsurplus steam may be generated to heat the coaches connected with thelocomotives, or to heat buildings, &c.

The invention consists of certain parts and details and combinations ofthe same, as will be hereinafter fully described, and then pointed outin the claims.

Reference is to be had to the accompanying drawings, forming a part ofthis specification, in which similar letters of reference indicatecorresponding parts in all the figures.

Figure 1 is a transverse section of a locomotive-boiler fire-box withthe improvement attached. Fig.2 is a sectional side elevation of thesame on the line as as of Fig. 1. Fig. 3 is an enlarged sectional Viewof part of the improvement on the line y y of Fig. 2, and

' Fig. 4 is a sectional plan view of part of the improvement on the line2 z of Fig. 1.

The boiler A, of any approved construction, is provided with the usualfire-box B,formed in the leg 0 of the boiler. To the inner shell D ofthe fire-box is secured one or more coils of pipe E, each provided onits lower end with a block F, set against the inside of the shell D andprovided with an opening F, registering with the corresponding openingD, formed in the inner shell D. In the inner end of the block F is set aplug H, held on a screw-rod I, passing through the openings F and E andthrough the water-space G of the boiler to the outside of the exteriorshell G.

, A nut 1 screws on the outer end of the screwrod 1, so as to securelyhold the block F against the inside of the inner shell D. Into theopenlowermost elbow E of the coil E. The pipe J and the said elbow arepreferably connected with each other by abolt K, so as to permit anextension of the coil of pipe E without injuring the connection of thepipe J with its block'F. Each coil of pipe E extends preferably alongthe inside of the inner shell D and then along the top of the same, theupper end of each coil being connected bya suitable joint (illustratedin Fig. 4:) with a pipe L,

curved downward and connected with the water-space G on the top of thefire-box B.

The operation is as follows: The heat in the fire-box B heats thefire-box and the tubes connected with the same in the usual manner, andat the same time heats the coils of pipe E, filled with water, whichpasses from the leg 0 of the boiler into the coil through the aperturesD F in theblock F to the pipe J, and from the latter to the lowermostelbow of the coil of pipe. The heated water circulates through the coilof pipe to finally pass into the pipe L, and from the latter dischargesinto the top of the water-compartment surrounding the top of thefire-box.

It will be seen that without additional expense of fuel the waterpassing through the coils of pipe E is heated, whereby sufficientsurplus of steam is generated to heat coaches connected with thelocomotive, or to heat buildings connected by suitable means with theboiler. It will further be seen that the device serves for filtering thewater in the boiler on account of the rapid evaporation of the water,which causes a strong current to flow from the leg of the boiler upwardthrough the coils of pipe, thus preventing sediment from settling in theleg of the boiler.

Having thus fully described my invention, I claim as new and desire tosecure by Letters Patent 1. The combination, with a boiler, of parallelseries of tubes extending longitudinally along the walls of thefire-box, the tubes of each series being connected to form a continuouspassage, and the lower tubes communicating with the legs of the boilerand the upper ones discharging into the upper part of the boiler belowits water-line, substantially as set forth.

2. The combination, with a boiler, of the tubes extending along thesides and top of the fire-box and connected to form a serpentinepassage, the connections between the lower side tubes and thewater-legs, and a connection between the top tubes and the water spaceof the boiler below the crown-sheet, substantially as set forth.

3. The combination, with the boiler, of the parallel connected tubes E,extending along the sides and top of the fire-box, the :tpertu redblocks having pipe J connected with the lower side pipes and with thelegs of the boiler,the bolts I, extending through the blocks nndlegs ofthe boiler to the outside, and the curved 10 pipe L, communicating withthe rear ends of the two inner upper pipes and with the waterspace ofthe boiler below the crown-sheet, substantially as set forth.

JOHN NELSON ROBERTS. Vitnesses:

\VA'ISON S. HILLS, FRANK L. SUTTON.

